Heating of the intracluster medium by quasar outflows

Abstract

We study the possibility of quasar outflows in clusters and groups of galaxies heating the intracluster gas in order to explain the recent observation of excess entropy in this gas. We show that radio galaxies alone cannot provide the energy required to explain the observations but the inclusion of Broad Absorption Line (BAL) outflows can do so, and that in this scenario most of the heating takes place at z ~ 1-4, the ``preheating'' epoch being at a lower redshift for lower mass clusters.